‘The handling of Brexit has been a story of unremitting and nationally humiliating failure.’
Photograph: Emmanuel Dunand/AFP/Getty

If ever there was a reason for the people of Britain to take to the streets to protest about the reckless hazarding of our country’s interests, the Conservative government’s Brexit failure during the past two years provides one. If ever there was a moment to insist, through a peaceful display of outrage, that Britain can do so much better by following a different course, this is it. And if ever there was a chance for the voices that Theresa May’s government has consistently snubbed and ignored to shift the agenda of the Brexit debate away from the fantasies of the fanatical few towards the practical priorities of the ordinary many, then Saturday’s People’s Vote March for the Future provides that opportunity.

Brexit is by any measure the most important change of strategic direction that this country has faced in more than 70 years. The people voted for it. But they did not vote for the terms of separation. Those remained to be negotiated, debated and agreed. The outcome of those negotiations with our European Union neighbours will shape the job prospects and life chances of anxious millions of Britons today and of future generations too. The terms on which the agreement is implemented will be pivotal to Britain’s – and Europe’s – shared ability, in a world where the rules-based order is increasingly under challenge, to deal with international problems ranging from banking stability and climate change to terrorism. The deal will also shape whether the United Kingdom – another union in which, as with the EU, our peoples have been better off together than apart – holds together or breaks into less consequential parts.

From almost the very moment that the referendum result was declared, the handling of Brexit has been a story of unremitting and nationally humiliating failure. The negotiations were said to be simple. But they weren’t. The EU would bend over backwards, it was said, to give Britain special favours. It wouldn’t. Other nations would beat a path to Britain’s door to strike trade deals. They didn’t. Under Theresa May, the Tory party would bring the nation back together after the referendum. That didn’t happen either, because Mrs May and the Tory party didn’t even try; instead they split ever more deeply. Not only has the government failed to strike a deal with the EU. It has even failed to reach a coherent agreement with its own MPs. As a result, Brexit threatens to be both a policy failure without precedent and a national betrayal whose reverberations will send tremors down the decades.

This was supposed to have been the week in which the government finally struck a deal with the European Union. Whether you support or oppose Britain’s departure from the EU – and this newspaper still opposes it – a deal would be a turning point for Britain. It might – possibly – have been the time when some of the country’s post-Brexit economic and security needs could have been agreed. It might – potentially – have allowed the long process of healing some of the Brexit divisions to begin. Instead, in Brussels this week, the moment simply came and went, with Mrs May’s government powerless to sign up.

This is not just another unfortunate slippage of a timetable. It is yet another unavoidable collision between Brexit fantasy and Brexit reality. Yet this one risks, now more than ever before, a completely unacceptable sacrifice of the national interest to the interests of the Tory party, in the form of a no-deal crash-out from the EU. From the start, Mrs May has told the Tory party that she could deliver a form of Brexit that was simply not achievable. Nearly half of the country did not want this in the first place. Many more have become alarmed at the chaos and incompetence with which it has been pursued.

The coming weeks will decide if Britain and the EU can forge a Brexit relationship that works for their peoples or not. Huge choices have to be made in parliament by MPs, perhaps including a second vote on the terms of any deal. All this is on the table. But the journey ahead requires leadership that neither main party has yet offered on an issue of such historic importance. Saturday is a day to bear witness to the urgent truth that Britain must have a far better future relationship with the rest of Europe than anything that Mrs May has come close to providing.